This book describes the key issues and technologies driving Web Services. It provides thorough coverage of concepts, issues, common problems and their solutions, technologies, and best practices necessary to build production-quality Web Services-based applications. Part 1 outlines the big picture for distributed computing environments. It reviews Web Services standards--such as SOAP, WSDL, and UDDI, highlighting key ideas that recur throughout the book. Building on the fundamentals, Part 2 introduces advanced technologies, including some emerging standards in important areas such as transactioning, security, mobile, and pervasive computing, and wireless environments. Drawing on experiences in developing real world Web Services-based applications, the authors present a set of best practices for application architectures based on this new distributed computing paradigm. Key technologies and recommendations are brought together by building an enterprise-scale Web Services-based application.